He said Thursday on MSNBC that the best way to bring democracy to Cubans is to let Americans "go there and trade and invest." Carter says that will show Cubans that Americans are "not the enemy."

Carter tried to normalize relations with Cuba shortly after taking office in 1977 by re-establishing diplomatic missions and negotiating the release of thousands of prisoners. But conflicts over Cuban military action in Africa and a flood of Cuban refugees in 1980 stymied those efforts, which ended when Ronald Reagan became president in 1981.